In a livestock business of cattle, to produce good calves a method comprising collecting internally fertilized eggs from a cow and transplanting the fertilized eggs into other cows is employed. Therefore, a method is performed, in which method a gonadotropin preparation is administered to a cow to induce superovulation, artificial insemination is conducted, and then fertilized eggs are collected.
Conventionally, at the practice of the above-described method, the gonadotropin preparation was administered to the cow multiple times. However, the multiple administrations of the gonadotropin preparation not only give the cow a lot of stress, but also give a lot of strain to veterinaries.
Therefore, the present inventors proposed, as disclosed in a bulletin of Japanese Patent No. 4408017, a preparation for cattle for inducing superovulation, which can induce superovulation by a single administration, and a method for producing good calves comprising a step of administering to cattle such a preparation for inducing superovulation. This preparation for inducing superovulation comprises aluminum hydroxide gel and a gonadotropin. The concentration of the aluminum hydroxide in this preparation for inducing superovulation is, in terms of the amount of aluminum, 1.0 to 5.0 mg/mL, and the administration dose per cattle is 10 to 50 AU in terms of the gonadotropin and 2 to 20 mL as an amount of the preparation for inducing superovulation. Thus, per cattle and per administration, 2 to 100 mg, in terms of the amount of aluminum, of aluminum hydroxide is administered. In the examples of the bulletin of Japanese Patent No. 4408017, the concentrations of the aluminum hydroxide in the preparations for inducing superovulation are, in terms of the amount of aluminum, 1.28 mg/mL and 1.44 mg/mL, the total amounts of the aluminum hydroxide per administration are, in terms of the amount of aluminum, 6.4 to 14.4 mg. Also, the method for producing good calves, which is disclosed in the examples of the bulletin of Japanese Patent No. 4408017, comprises administering to a cow the preparation for cattle for inducing superovulation by intramuscular injection.
Here, there are subcutaneous, intradermal and intramuscular routes as administration ones of a medicament by injection. A bulletin of Japanese Patent Laid-open No. 2005-281245 discloses subcutaneously administering to an animal once a sustained-release formulation for follicle-stimulation that comprises aluminum hydroxide gel and a follicle stimulation hormone, although it is a method comprising inducing superovulation in an experimental animal such as a rabbit. In the bulletin of Japanese Patent Laid-open No. 2005-281245, the concentration of the aluminum hydroxide in the sustained-release formulation for follicle-stimulation is, in terms of the amount of aluminum, 1 to 10 mg/mL, and the total amount of the aluminum hydroxide per administration is, in terms of the amount of aluminum, 0.1 to 50 mg. Moreover, in the examples, the concentration of the aluminum hydroxide is, in terms of the amount of aluminum, 3 mg/mL, and the total amount of the aluminum hydroxide per administration is, in terms of the amount of aluminum, 4.5 mg.
In a bulletin of Fukuoka Agriculture Research Center 26, an examination result is disclosed, wherein the result was obtained by subcutaneously administering to a cow once a preparation obtained by adsorbing a follicular stimulating hormone derived from porcine to aluminum hydroxide gel, and then evaluating the transition of the concentration of the follicular stimulating hormone derived from porcine in plasma of the cow. In this examination, the concentration of aluminum is 1.3 mg/mL, and the single administration dose per cattle is 30 AU in terms of the follicular stimulating hormone and 12.5 mL or 5 mL as a volume of the subcutaneous injection product. Thus, the total amount of the aluminum hydroxide is, in terms of the amount of aluminum, 16.25 mg or 6.5 mg.
As stated above, aluminum hydroxide has been used to release the gonadotropin slowly. However, an appropriate concentration of the aluminum hydroxide in the gonadotropin preparation and an appropriate total amount of the aluminum hydroxide in the single administration have not necessarily been studied.